Electrical energy —> Thermal energy
Electrical energy —> thermal energy via heating elements in heating appliances such as electric radiator, electric iron, electric hotplate and electric kettle
Power
P = VI = I^2R = V^2 / R
Energy
E = VIt = I^2Rt = V^2 / R t
Dangers of electricity
Overheating of cables
2. Use of inappropriate wires
Safety features
Live wire
Brown
240V
Circuit breakers, fuses and switches are fitted
Neutral wire
Blue
0V
Earth wire
Green and yellow
Low-resistance
Double insulation
2. External casing
Why should the earth wire be connected to the metal casing
If the live wire breaks and touches the metal casing, the earth wire carries the current away and prevents the user from getting an electric shock